Yeah, but if you have the Blowfish source code - which had an integer signing bug in it for 10+ years that nobody had caught - it doesn’t mean that you KNOW if what you are sending is secure. All those libraries and encryption in general is “magic” to most people.
It's really subtle stuff.
One isolated flaw aside, the point remains: serious encryption is available to users even if government forbids it. Yes, Blowfish had a bug - but there are numerous other well-regarded thoroughly-studied strong-encryption algorithms available ... and they’re so simple I have several on t-shirts.
Encryption will always have the risk of either bad implementation, or mathematical breakthroughs, compromising security. It’s generally accepted that implementations should be open-source (not necessarily _free_) for examination, so such flaws may be publicly discovered ASAP.
Yes, it’s magic to most users. That’s why we need a sense of trust - which we DON’T have when strangers with guns compel us to compromise our security for their benefit, especially when they’re making the demands after they failed to do a bunch of other things we’ve given them authority to do.
If I were actually to do this, I’d probably download something more current. I just downloaded the Blowfish because I wanted to study the encryption techniques it uses.